listening ear 150x150 The Potential of Gene Therapy to Restore Hearing Loss Imagine that you are born deaf and live in a world of silence – what price would you pay for a new treatment that might restore your hearing?

That is the market opportunity that may be available for biotechnology and pharmaceutical companies as the basic science around congenital hearing loss starts to yield insights that could translate into new products.

Research published in the July 26, 2012 issue of the journal “Neuron” by Omar Akil from UCSF and colleagues at the University of Pittsburgh and Ohio State University, showed the ability to reverse hearing loss in mice through the use of gene therapy (viral-mediated insertion) to replace the absent vesicular glutamate transporter-3 gene (VGLUT3).

VGLUT3 is a gene involved with the transport of the neurotransmitter glutamate that is required by inner hair cells in order to generate neural responses to sound. Mice lacking VGLUT3 can’t hear.

Insertion of the VGLUT3 gene into mice cochlear cells resulted in restoration of hearing that lasted for 9 months (that’s a long time for mice). The authors noted that:

“These findings represent a successful restoration of hearing by gene replacement in mice, which is a significant advance toward gene therapy of human deafness.”

Over 50% of all human hearing loss is genetically based, and as tools to understand the human genome develop, scientists have been able to identify a number of genes associated with hearing loss.

Research in animal models is ongoing, with the potential in the future that we may be able to replace, repair or correct a defect a genetic mutation.

Could this lead to the restoration of human hearing? The answer is “yes”.

An accompanying editorial in Neuron by Donna Martin and Yehoash Raphael from The University of Michigan describes the work by Akil and colleagues as a major breakthrough:

“Results presented in their paper are a true breakthrough because they show that gene therapy can lead to functional recovery from sensorineural deafness. Even more exciting is the direct relevance of this work to a large population of humans who have mutations in the VGLUT3 gene.”

There remain a number of challenges before gene therapy to correct human deafness becomes a reality, but biopharmaceutical companies such as GenVec (NASDAQ: GNVC) already see the market opportunity and potential for gene therapy to correct hearing loss. Novartis have a collaboration agreement with GenVec that is worth up to $213.6M in milestone payments.

The potential of gene therapy to restore hearing loss will offer hope to many with deafness. It is an exciting area to watch as innovative science translates into personalized medicine.

References

rb2 large gray The Potential of Gene Therapy to Restore Hearing Loss Omar Akil, Rebecca P. Seal, Kevin Burke, Chuansong Wang, Aurash Alemi, Matthew During, Robert H. Edwards, & Lawrence R. Lustig (2012). Restoration of Hearing in the VGLUT3 Knockout Mouse Using Virally Mediated Gene Therapy Neuron, 283-293 DOI: 10.1016/j.neuron.2012.05.019

Donna M. Martin, & Yehoash Raphael (2012). Have You Heard? Viral-Mediated Gene Therapy Restores Hearing Neuron, 75, 188-190 DOI: 10.1016/j.neuron.2012.06.008